heap_management.c

/*
	Author: Tarun Jain
	Roll Number: MT2015120
	File: RTOS Assignment 1 - Question 1 -Main File/ Test Case File
	Problem Statement: Implement the malloc, free, calloc, realloc Function using your own Heap(Static array of 10240 Bytes)
*/

// Header Files
#include "heap_management.h"

// Global Variable
void *base = NULL;			// For Base Address of Heap

// Initialization Function
void init()
{
	limit = memory;
	end_limit = (memory + MEM_SIZE);	
}

// Demonstrate Memory Allocation/Deallocation/Reallocation/Free
void demo()
{

	
	int *p1	= NULL;				// To Store Integer Address
	float *c1 = NULL;			// To Store Float Address
	double *f11 = NULL;			// To Store Double Address
	float *z1 = NULL;			// To Store Float Address
	int *p2 = NULL;				// For Calloc 
	int i;					// Loop Variable
	void *zero =NULL;			
	
	printf("\nRequesting Integer Space ...\n");
	p1 = (int *)my_malloc(sizeof(int));
	// If no memory available
	if( !p1)
	{
		printf("Integer Malloc Failed.\nTerminating ...\n");
		exit(0);
	}
	printf("Integer Memory Allocation Successful: %p\n", p1);
	
		
	printf("\nRequesting Float Space ...\n");
	c1 = (float *)my_malloc(sizeof(float));
	// If no memory available
	if( !c1)
	{
		printf("Float Malloc Failed.\nTerminating ...\n");
		exit(0);
	}
	printf("Float Memory Allocation Successful: %p\n", c1);
	
	
	printf("\nRequesting Double Space ...\n");
	f11 = (double *)my_malloc(sizeof(double));
	// If no memory available
	if( !f11)
	{
		printf("Double Malloc Failed.\nTerminating ...\n");
		exit(0);
	}
	printf("Double Memory Allocation Successful: %p\n", f11);
	
	printf("\nRequesting Zero Bytes Space ...\n");
	zero = my_malloc(0);
	// If no memory available
	if( !zero)
	{
		printf("Can't Allocate Zero Byte.\n");
	}
	printf("Double Memory Allocation Successful: %p\n", f11);
	
	printf("\nRe-alloc with NULL as Address - Behaves as Malloc ...\n");
	zero = my_realloc(NULL,10);
	// If no memory available
	if( !zero)
	{
		printf("Re-alloc Failed.\nTerminating ...\n");
		exit(0);
	}
	printf("Double Memory Allocation Successful: %p\n", f11);
	
	printf("\nRemaining Size in Heap:%lu\n\n", free_space());
	
	printf("\nReallocating Float Space ...\n");
	z1 = (float *)my_realloc(c1, 5 * sizeof(float));
	// If no memory available
	if( !z1)
	{
		printf("Re-alloc Failed.\nTerminating ...\n");
		exit(0);
	}
	printf("Float Re-Allocation Successful: %p\n", z1);
	
	// Just for Address Computation
	char *uv = (char *) z1;
	uv = uv - BLOCK_SIZE;
	struct block *uv1 = (struct block *)uv;
	
	printf("Size of realloced space: %lu and address: %p", uv1 -> size, z1  );

	printf("\n\nRemaining Size in Heap:%lu\n", free_space());
	
	printf("\nRequesting Calloc Memory Allocation...\n");
	p2 = (int *) my_calloc( (size_t)10, sizeof(int));
	for( i = 1; i <= 10 ; i++)
		p2[i] = i;
	for( i = 1; i <= 10 ; i++)
		printf("%d\t", p2[i]);

	printf("\n\nStatus of Heap After Allocation of Memory:\n");
	printf("Remaining Size in Heap:%lu\n\n", free_space());
	struct block * tally = (struct block*)base;
	while(tally)
	{
		printf("Meta Data Begins:%p\t", tally);
		printf("Size of Block: %ld\t", tally->size);
		printf("Free : %d\t", tally->free);
		printf("Next: %p\t", tally -> next);
		printf("Previous: %p\t", tally -> prev);
		tally = tally -> next;
		printf("\n");
	}

	printf("\nFree Up Double Space ...\n");	
	free(f11);
	printf("After Free up of Double Space ...\n");
	printf("\n\nStatus of Heap after Free Up of Memory:\n");
	printf("Remaining Size in Heap:%lu\n\n", free_space());
	tally = (struct block*)base;
	while(tally)
	{
		printf("Meta Data Begins:%p\t", tally);
		printf("Size of Block: %ld\t", tally->size);
		printf("Free : %d\t", tally->free);
		printf("Next: %p\t", tally -> next);
		printf("Previous: %p\t", tally -> prev);
		tally = tally -> next;
		printf("\n");
	}
	printf("\nDefragmentation Started ...\n\n");
	defragment_my_heap();
	tally = (struct block*)base;
	printf("\nAfter Defragmenting the Heap: \n");
	while(tally)
	{
		printf("Meta Data Begins:%p\t", tally);
		printf("Size of Block: %ld\t", tally->size);
		printf("Free : %d\t", tally->free);
		printf("Next: %p\t", tally -> next);
		printf("Previous: %p\t", tally -> prev);
		tally = tally -> next;
		printf("\n");
	}
	printf("\n");
}

// Main Function
int main()
{
	// Initialization
	init();
	// Demonstration
	demo();
	return 0;
}